Background: Statins have potent anti-inflammatory effects in laboratory studies of pulmonary inflammation. We investigated whether statin users had improved outcome when admitted with community-acquired pneumonia.
Methods: We carried out a prospective observational study of patients admitted to the hospital with community-acquired pneumonia between January 2005 and November 2007. The use of statins, angiotensin-converting enzyme inhibitors, beta-blockers, and aspirin were recorded. The outcomes of interest were 30-day mortality, need for mechanical ventilation or inotropic support, and the development of complicated pneumonia.
Results: On multivariate logistic regression, statin use was associated with significantly lower 30-day mortality (adjusted odds ratio [AOR] 0.46, 95% confidence interval [CI], 0.25-0.85, P=.01) and development of complicated pneumonia (AOR 0.44, 95% CI, 0.25-0.79, P=.006). There was no effect on requirement of mechanical ventilation or inotropic support (AOR 0.93, 95% CI, 0.49-1.76, P=.8). Patients prescribed statins had more severe pneumonia (median Pneumonia Severity Index 4, interquartile range [IQR] 3-4) compared with patients not prescribed cardiovascular drugs (median Pneumonia Severity Index 3, IQR 2-4, P < .0001). Despite this, C-reactive protein levels on admission were significantly lower in patients prescribed statins (median 119 mg/L, IQR 46-215) compared with patients prescribed no cardiovascular drugs (182 mg/L, IQR 66-326, P < .0001). On multivariate logistic regression, statin use was independently protective against a C-reactive protein that failed to fall by 50% or more at day 4 (AOR 0.50, 95% CI 0.27-0.92, P=.02).
Conclusions: Statin use is associated with reduced markers of systemic inflammation and improved outcomes in patients admitted with community-acquired pneumonia.